The performance of aerodynamic structures depends primarily on the lift and drag forces created at the surface of the structures in response to passing air flow. Mechanically fixed surfaces may be selectively included at aerodynamic surfaces, such as rotor blades, wings, engine inlets, fan blades, nozzles, etc., in order to alter local aerodynamic properties and thus achieve desired aerodynamic properties for those aerodynamic structures. Additionally, movable control surfaces, such as flaps, slats, spoilers, ailerons, elevators, and rudders, may be included in or on the aerodynamic surfaces in order to dynamically alter the geometry of the aerodynamic surface, thus altering the aerodynamic properties of the structure.
Beyond the various mechanical means included on aerodynamic structures, aerodynamic properties of the structures may also be altered by causing effects on the passing air flow. These effects may be generated by various actuating devices disposed in or on the aerodynamic surface or device.